In 2013, the European Space Agency (ESA) deployed the Gaia mission, a space observatory designed to measure the positions of movements of celestial bodies. For the past four years, Gaia has been studying distant stars, planets, comets, asteroids, quasars and other astronomical objects, and the data it has acquired will be used to construct the largest and most precise 3D space catalog ever made, totaling 1 billion objects.

The second release of Gaia data, which took place on April 25th, 2018, has already resulted in a number of impressive discoveries. The latest was made by an international team of scientists who identified 13,928 white dwarfs within 100 parsecs (326 light-years) of the Sun, many of which were formed through mergers. This is the first time that white dwarf stars have been directly detected within the Solar neighborhood.

Study - Findings - Gaia - Reveals - Evidence

The study which describes their findings, “Gaia Reveals Evidence for Merged White Dwarfs“, recently appeared online and is being considered for publication in the Monthly Notices of the Royal Astronomical Society. The study was led by Dr. Mukremin Kilic, an associate professor at the University of Oklahoma, and included members from the Institute for Astronomy at the University of Edinburgh and the University of Montreal.

Basically, white dwarfs are what become of the majority of stars (with masses less than 8 Solar masses) once they exit the main sequence phase of their lives. This consists of a star exhausting its hydrogen fuel and expanding to several times its size (entering its Red Giant Branch Phase). These stars then blow off their external layers (a supernova) and leaving behind a white dwarf remnant.

Astronomers - Life - Cycle - Stars - Dr

By studying them, astronomers can learn far more about the life cycle of stars and how they evolve. As Dr. Kilic explained to Universe Today via email: